In 1996, a Flight Was Cleared to Climb to 14,000 Feet After Takeoff. Then the Deadliest Mid-Air Collision in History Occurred

On 12 November 1996, a tragic mid-air collision between a Saudi Arabian Airlines flight and a Kazakhstan Airlines aircraft claimed the lives of all 349 individuals on board both planes. This catastrophic event marked one of the deadliest incidents in aviation history, as debris from the two jets scattered across the Indian farmland below.

The incident occurred as Saudi Arabian Airlines Flight SV763 was preparing to take off from Indira Gandhi International Airport (DEL) in New Delhi, embarking on a journey to Dhahran, Saudi Arabia. The flight, operated by a Boeing 747, was carrying 312 passengers and crew. Concurrently, Kazakhstan Airlines Flight 1907, serviced by a four-year-old Ilyushin Il-76TD, was approaching from Shymkent, Kazakhstan, with 37 people on board.

As the Kazakhstan flight neared the airport, the crew received clearance to descend to 15,000 feet. Meanwhile, the Saudi Arabian jet was authorised for takeoff and to climb to 14,000 feet. Within minutes of the Saudi flight’s departure, however, the two aircraft collided. An air traffic controller later reported observing “two blips merging on the radar screen but not separating,” followed by the abrupt disappearance of both aircraft’s signals around 6:40 PM.

Eyewitness accounts, including one from a United States Air Force pilot bringing supplies to the American Embassy in New Delhi, described the harrowing aftermath of the crash. The pilot reported seeing a large cloud illuminated by an orange glow, which intensified before two fireballs erupted and fell toward the fields below.

The subsequent investigation revealed critical miscommunications that contributed to the tragedy. The crew of the Kazakhstan Airlines flight descended approximately 1,000 feet below the assigned altitude, positioning their aircraft directly in the flight path of the Saudi plane. Investigative documents indicated that, just 26 seconds prior to the collision, the Kazakhstan flight’s altitude was recorded at 14,190 feet.

Furthermore, the transcripts from the cockpit indicated that the crew of the Kazakhstan Airlines flight did not confirm whether they had received or were adhering to the instructions from air traffic control to maintain the designated altitude. Although the airline initially cited “severe air turbulence” as a factor, this claim was contested by the Saudi pilots, who noted the absence of any turbulence in the cockpit audio recordings.

Language barriers played a significant role in the confusion leading up to the collision. The Russian-speaking crew of the Kazakhstan Airlines flight communicated in English, which may have compounded misunderstandings. Increased complexity arose from the aircraft’s altimeter being marked in metric measurements, necessitating conversions that could lead to operational errors, particularly under stress.

The incident also raised serious concerns about the adequacy of India’s air traffic control systems at the time. Controllers relied on aging radar technology that provided limited information regarding the altitude or direction of the aircraft, only indicating distances from the airport. Although new American-made radar systems were scheduled for installation at major airports including those in New Delhi, Mumbai, and Kolkata, delays in the upgrade left controllers dependent on pilots to accurately report their own altitudes.

As aviation authorities scrutinised the tragedy, recommendations for improvements in air traffic control technology and crew communication protocols emerged. The collision highlighted the need for robust safety standards and effective training for flight crews, especially in multilingual communication settings.

The memory of those lost in the crash serves as a stark reminder of the vulnerabilities inherent in aviation operations. The lessons learned from the collision continue to inform safety regulations and procedures worldwide, with the aim of preventing such devastating incidents from occurring in the future. The legacy of the November 1996 disaster remains etched in the history of aviation safety, underscoring the importance of clear communication and operational diligence.